Scaffold plank

ABSTRACT

An extrudable cross-section is adapted for use as a scaffold plank. Bending stiffness is obtained by using an undulated crosssectional configuration that is stackable without jamming. A plurality of these planks may be interengaged along the edges for transfer of forces so that each plank is assisted by those adjacent to it.

United States Patent Williams May 20, 1975 [541 SCAFFOLD PLAN FOREIGN PATENTS OR APPLICATIONS lm'enmrl ch95!" Wi||iam$- Madison 1.021.996 1/1958 Germany 8. 52/173 51.. Grand Rapids. Mich 49507 [22] Filed; Oct 1. 1973 Primary E.\'aminer-Reinald0 F. Machado Arturney, Agent, or FirmGlenn B. Morse [2|] Appl. No.: 402,614

[57] ABSTRACT [52] US. Cl. 182/222; 52/588; 182/ I78 An extrudable cross-section is adapted for use us a [5!] Int. Cl. E04g 5/08; E04g l/l6 aff l pl nk. Bending tiffne s is obtained by using [58] Field of Search 182/222, 178; 52/588, I73 an undulated cross-sectional configuration that is stackable without jamming. A plurality of these planks [56] References Cit d may be interengaged along the edges for transfer of UNITED STATES PATENTS fences so that each plank is assisted by those adjacent 3.368.315 2/1968 Thurnuu 52/588 to 3.466.832 9/1969 March 52/588 2 Claims, 7 Drawing Figures SCAFFOLD PLANK BACKGROUND OF THE INVENTION Scaffolding is used in construction work wherever it is necessary to provide a temporary platform to support workmen and equipment. Because of its temporary nature, it is important that the scaffolding components be reusable and easily installed and removed. The cost of erecting and reerecting scaffolding is obviously closely associated with the number of support points provided for the platform, and it is therefore important that the platform itself have a substantial amount of bending rigidity so that the number of these support points can be minimized. These components should also be stackable compactly and solidly for economy of storage space.

Situations are often encountered in structural design work where it becomes desirable to interengage the edges of long members for the transfer of forces from one member to the other. The usual arrangement for providing this feature involves interengaging opposite ends of adjacent members, and then applying relative axial movement to bring the two members in side-byside position. Sheet piling is an example of this type of interengagement, which is undesirable for use in conjunction with members used as scaffolding planks in view of this endwise interengagement.

SUMMARY OF THE INVENTION To combine stacking characteristics and bending stiffness, an extruded cross section is defined by oppositely inclined webs interconnected at their points of closest approach by flat sections forming the top and bottom of the plank element. The top sections are preferably wider than the bottom, and stop lugs are provided on the webs to receive the bottom sections on stacking. The opposite edges of the planks have a configuration that is laterally interengageable on inclination of successive planks at installation to form a platform. Placement of the stop lugs and the surfaces engaged by them maintains parallelism of the planks on stacking.

DESCRIPTION OF THE DRAWING FIG. I is an end elevation of two plank elements embodying the invention, shown interengaged at their meeting edges to form a platform.

FIG. 2 is a fragmentary view on an enlarged scale of the left-hand edge of the plank elements shown in FIG. 1.

FIG. 3 is a fragmentary end elevation on the scale of FIG. 2, showing the right-hand edge of the plank elements appearing in FIG. 1.

FIG. 4 is a fragmentary end elevation on the scale of FIGS. 2 and 3 showing an intermediate position in the interengagement of the plank elements.

FIG. 5 is a fragmentary end elevation on the scale of FIG. 4, showing the completely assembled relative placement of the plank elements.

FIG. 6 shows the plank elements of FIG. 1 in stacked relationship.

FIG. 7 is a fragmentary end elevation showing a modified top surface configuration of the plank elements.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The plank elements generally indicated at 10 and II in FIG. 1 are identical, and have an undulated crosssection defined by the successive relatively inclined webs l2 and 13 interconnected by the upper sections 14 defining the top of the plank element, and by the lower sections 15 forming the bottom of the plank element. Both the sections 14 and 15 interconnect the webs at their points of closest approach.

The interengagability of the plank elements 10 and 11 is provided by the edge configurations shown in FIGS. 2 and 3. The left-hand edge of the plank elements is defined by the flange 16 having an offset 17 defining a recess 18. At the opposite edge of the plank element, an outer flange 19 extends outwardly from the edge of the web 13 in the plane of the lower sections 15, the outer flange l9 terminating at its outer end in an edge offset 20. An inner flange 21 is spaced from the flange 19 by an amount sufficient to receive the flange 16 with sufficient clearance to accomodate the relative angular displacement shown in FIG. 4. It is preferable that the web 12 be extended downward to a point of tangency with the plane defining the bottom surfaces of the sections 15 and the flange 19 (which are coplanar).

In the assembly of a platform using the plank elements described above, the element 10 is first placed in position on convienent supports. The element 11 is then moved laterally into a position where the flange 16 can hook under the inner flange 21 of the plank 10 in the position shown in FIG. 4. The plank element 11 is then rotated clockwise to the position shown in FIG. 1. As thus interengaged, each plank assists the other in supporting whatever load may be present on the platform. Neither plank element can be deflected in bending without inducing similar deflection in the plank with which it is interengaged. As can be seen from FIGS. 4 and 5, the outer and inner flanges 19 and 21, respectively, are spaced apart by a distance substantially equal to the thickness of the flange l6 and the flange I6 is offset from the plane of the lower sections 15 by a distance substantially equal to the thickness of the outer flange 19. The relative lengths of the flange l6 and the outer flange 19 are such that the outer edge of the flange 16 extends fully into the groove formed by the outer flange l9 and inner flange 21 while the edge offset 20 of outer flange 19 mates with the recess 18.

The stacking characteristics of the plank elements are provided by the lugs 22 at an intermediate position on the sides of the webs 12 and 13 which place these lugs directly above the lower sections 15, and thus are disposed to engage these sections when the planks are placed in the stacked position shown in FIG. 6. The lugs also receive the lower extensions of the webs 12 and 13 along the edges of the plank elements. This arrangement provides a solid stacked condition that prevents any wedging as increased weight is added by successively stacked plank elements. The placement of the lugs 22 is such as to form an abutment that limits relative vertical movement to a position such that the webs I2 and 13 cannot bind together.

FIG. 7 shows a modification of the invention that is particularily useful when the scaffolding is to be used primarily as a platform for workmen. The upper section 23 is provided with the serrated top surface 24. This configuration tends to produce a much more reliable footing, particularily in rainy conditions. The undulated cross section of the planks forms convienent channels for conducting rain water, or for accumulating foreign particles. either one of which might interfere with the footing for the workmen,

I claim:

1. A stackable scaffolding plank having a crosssection adapted for extrusion. said scaffold plank having a plurality of inclined first and second web portions and a plurality of upper and lower sections interconnecting adjacent web portions at the points of closest proximity therebetween. said sections and web portions being disposed to define an undulated configuration. wherein the imprmement comprises:

a first interlock portion extending along one edge of said plank and including an outer flange coplanar with said lower sections. the free edge of said outer flange having an edge offset. and an inner flange spaced from. extending parallel to. and shorter than. said outer flange;

a second interlock portion. extending along the opposite edge of said plank from said first interlock portion. adapted to mate with the first interlock portion of an adjacent scaffold plank. and including a flange having a part thereofextending parallel to and receivable between said inner and outer flanges of the first interlock portion of said adjacent similar plank. said part of said flange being spaced from the plane of said lower sections b a distance substantially equal to the thickness of said outer flange. and also having a recess normall receiving the edge offset of said similar plank. and

abutment means disposed at intermediate positions on said first and second web portions to engage said lower sections of a similar plank with said undulated configurations interengaged. said abutment means extending laterally to limit the depth of interengagement of said configurations.

2. A plank as defined in claim 1. wherein said upper sections are substantially greater in width than said lower sections. and said abutments are disposed to receive said lower sections on stacking a plurality of said planks. 

1. A stackable scaffolding plank having a cross-section adapted for extrusion, said scaffold plank having a plurality of inclined first and second web portions and a plurality of upper and lower sections interconnecting adjacent web portions at the points of closest proximity therebetween, said sections and web portions being disposed to define an undulated configuration, wherein the improvement comprises: a first interlock portion extending along one edge of said plank and including an outer flange coplanar with said lower sections, the free edge of said outer flange having an edge offset, and an inner flange spaced from, extending paralLel to, and shorter than, said outer flange; a second interlock portion, extending along the opposite edge of said plank from said first interlock portion, adapted to mate with the first interlock portion of an adjacent scaffold plank, and including a flange having a part thereof extending parallel to and receivable between said inner and outer flanges of the first interlock portion of said adjacent similar plank, said part of said flange being spaced from the plane of said lower sections by a distance substantially equal to the thickness of said outer flange, and also having a recess normally receiving the edge offset of said similar plank; and abutment means disposed at intermediate positions on said first and second web portions to engage said lower sections of a similar plank with said undulated configurations interengaged, said abutment means extending laterally to limit the depth of interengagement of said configurations.
 2. A plank as defined in claim 1, wherein said upper sections are substantially greater in width than said lower sections, and said abutments are disposed to receive said lower sections on stacking a plurality of said planks. 